Extend the Growing Season

Looking for ways to extend the growing season? By warming the soil and protecting plants from the rain and cold, gardeners can gain weeks or months of additional growing time in early spring, fall, and winter.

Season extension does not need to be costly—especially when you use scrap and natural materials already at hand. Mulches, raised beds, wind protectors, and surroundings designed to capture the sun’s heat are just a few of the low-cost and no-cost ways available to resourceful gardeners. (Article continues below slideshow.)

Slideshow: 10 Ways to Extend the Growing Season

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Leaf mulch warms a row of parsnip plants in winter. Dark-coloured mulches such as leaves, wood chips, or black plastic will warm the soil more than light-coloured materials.

Mulch, such as straw or dried grass clippings, can warm the soil during cold seasons and help retain soil moisture during hotter months. When mulching around plants, take care to leave air space around the stems.

Burlap coffee sacks, (available free from coffee roasters) make good mulch material or pathway liners. In addition to warming the soil, they also help to suppress weeds.

Water-filled containers, such as 2-liter plastic milk jugs, can help warm seedlings. During the day the sun heats the water in the jugs. This continues to provide warmth and wind protection for the plant after the sun goes down.

Cold frames will stand up to wind, rain and snow to provide warmth and protection for plants throughout the winter. Old windows are excellent choices for cold frame tops. Scrap wood, hay bales, large stones, or bricks make good materials for the frame.

Hoop-style covered supports that span across a garden bed can protect seedlings or established plants. Thick-gauged wire, fiberglass garden rods or bent pvc pipe can form the supports. Plastic tarps (3 mil or higher), bed sheets, or Reemay (a polyester fabric that allows in light) are common coverings.

Wind protection can make a huge difference, especially in early spring. Planting near existing walls or fences offers protection against cold wind. You can also build temporary wind breaks with plastic or other materials.

Traditional cloches are bell-shaped glass covers placed over individual plants to protect them. Translucent plastic 4-liter milk jugs with the bottoms cut out will serve the purpose. By removing the cap, air can circulate in the cloche, while still providing warmth. A tall stick through the opening helps to anchor the cloche.

Raised garden beds, whether built in neat cedar boxes or by simply mounding up soil, will capture the warmth of the sun and give plants an advantage. The cool air sinks down to the surrounding pathways. Adding stones or gravel to the surrounds is another way to capture heat.

Plants situated against a sunny south-facing wall or fence often bear fruit larger and longer than in less protected areas. With extra warmth and wind protection, these locations are especially good for heat-loving plants like tomatoes and peppers.

Season Extension Techniques for Spring, Fall, and Winter Vegetable Gardens

If you like to eat fresh vegetables throughout the colder months, here are some ways to extend the growing season in your garden:

Raised Beds

Plant on raised beds. Raised beds can be as low-tech as simply mounding up the soil by several inches. Any height above the surrounding soil level will capture the warmth of the sun and give plants an advantage. The cool air sinks down to the surrounding pathways. Adding stones or gravel around the edges of the beds will help to capture additional heat and extend the growing season.

Mulch

Covering the garden with mulch can warm the soil during the cold season. Dark-coloured mulch warms the soil more than light-coloured material. Mulches include leaves, dried grass clippings, straw (not hay, which may introduce weeds), burlap coffee sacks (available free from coffee roasters), and wood chips. When mulching around plants, take care to leave air space around the plant stems so they do not stay wet.

Wind Protection and Sun Traps

Wind protection can make a huge difference, especially during windstorms. Everyday structures can offer protection against cold wind. Plants situated against a sunny south-facing wall, inside a sunny fenced area, or shielded from wind by taller plants may have a better chance to thrive.

Cloches to Extend the Growing Season

Traditional cloches are bell-shaped glass covers placed over individual plants to warm and protect them. If you want to save money, the recycle bin offers a number of useful items. Clear plastic 2-litre bottles or 1-gallon plastic milk jugs with the bottoms cut out will serve the purpose. By removing the cap at the top, air can circulate in the cloche, while still providing warmth. A tall stick through the opening helps to anchor the cloche in place.

Water-Filled Containers to Warm Plants

Half-gallon plastic milk jugs or 2-litre bottles filled with water can warm your plants in a number of ways. The sun warms the water inside, which continues to provide warmth and wind protection for the plant after the sun goes down. A circle of water-filled 2-litre bottles lashed together with clear packing tape creates a do-it-yourself Wall-o-Water—great for young tomato plants. Water-filled half-gallon jugs on their sides will warm seedlings and newly planted starts.

Cold Frames

Cold frames protect plants from cold, wind and rain. Hardy vegetables can survive and thrive all winter in a cold frame.

Cold frames will stand up to wind, rain and snow to provide warmth and protection for plants throughout the winter, as long as there is sufficient light. Old windows or bubble skylights are excellent choices for cold frame tops. Choose a window that opens or has a hinge so you can vent the cold frame when it gets too warm. Orient the window at a slant toward the south to get as much sun as possible. Gardeners build cold frames out of all kinds of materials, permanent and non-permanent, including wood, hay bales, large stones, or bricks.

Tunnels, Hoop Houses, or Row Covers

These generally use hoop-style or rectangular covered supports that span across a garden bed to protect seedlings or established plants. Thick-gauged wire, fiberglass garden rods, bent PVC pipes, wood nailed together to make a frame, or branches can form the supports. Plastic tarps (3 mil or higher), bed sheets, or Reemay (a polyester fabric that allows in light) are common coverings. It’s important to anchor the bottom the edges of the hoop house with something heavy such as water-filled bottles, rocks or bricks. Supports and coverings must be able to withstand wind storms; stakes will not stay put in windy coastal areas. However, double hoops—most of the hoops under the covering and a few hoops over the cover—will prevent the wind from blowing open your tunnels.

More on gardening:
Protect your Garden from Heat, Cold, Wind and Rain

Grow a Climate Change Resilient Garden

Growing a Patio Lemon Tree in Winter

10 Tips for Year-Round Vegetable Gardens